I have an RM20 combo.
I have built a new box to house the chassis, basically use it as an RM20 head.

I'm wondering what to do about the speaker jacks.
My amp has an external speaker jack on the back (activated when the standby switch is set to Silent)

it also has a red wire and a green wire that come directly off the chassis. They have spade terminals on the end and connect to the speaker in the combo.
This output is activated if you set the standby switch to Live.

Looking at some pics of RM20 heads online I would have thought they would have had two speaker jacks on the back. But they don't. However, they seem to have the same 3 position (Live/Standby/Silent) standby switch.

So am I safe to just have nothing connected to these red and green wires. Does the amp have a dummy load in it that will stop anything bad happening if the Standby switch is set to Live?
How does the RM20 head's standby switch work?

Alternatively I guess I could fix a jack with the male spade terminal connectors to the amp cabinet I've built and use that instead?